/*
 * @(#)StopWatch.java	1.0 Mar 7, 2008
 *
 *	The MIT License
 *
 *	Copyright (c) 2008 Malachi de AElfweald <malachid@gmail.com>
 *
 *	Permission is hereby granted, free of charge, to any person obtaining a copy
 *	of this software and associated documentation files (the "Software"), to deal
 *	in the Software without restriction, including without limitation the rights
 *	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 *	copies of the Software, and to permit persons to whom the Software is
 *	furnished to do so, subject to the following conditions:
 *
 *	The above copyright notice and this permission notice shall be included in
 *	all copies or substantial portions of the Software.
 *
 *	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 *	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 *	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 *	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 *	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 *	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 *	THE SOFTWARE.
 */
package org.eoti.util;

import static java.util.concurrent.TimeUnit.*;

public class StopWatch
{
	protected enum Cutoff
	{
		ns(MILLISECONDS.toNanos(1)){public String format(long time){return String.format("%s %s", time, this);}},
		ms(SECONDS.toNanos(10)){public String format(long time){return String.format("%s %s", NANOSECONDS.toMillis(time), this);}},
		sec(MINUTES.toNanos(3)){public String format(long time){return String.format("%s %s", NANOSECONDS.toSeconds(time), this);}},
		min(HOURS.toNanos(3)){public String format(long time){return String.format("%s %s", NANOSECONDS.toMinutes(time), this);}},
		hours(null){public String format(long time){return String.format("%s %s", NANOSECONDS.toHours(time), this);}};

		Cutoff(Long time)
		{
			if(time == null) time = Long.MAX_VALUE;
			this.time = time;
		}
		public abstract String format(long time);
		protected long time;
		public long getTime(){return time;}
	}
	protected static long ChronosCutOff_NS = MILLISECONDS.toNanos(1);
	protected static long ChronosCutOff_MS = SECONDS.toNanos(10);
	protected static long ChronosCutOff_SEC = MINUTES.toNanos(3);
	protected static long ChronosCutOff_MIN = HOURS.toNanos(3);

	protected long startTime;
	protected long stopTime;

	public StopWatch(){}

	public void start(){startTime = System.nanoTime();}
	public void stop(){stopTime = System.nanoTime();}

	/* getRunningTime() returns the difference as nanoseconds as per System.nanoTime() */
	public long getRunningTime(){return (stopTime - startTime);}


	public String report()
	{
		stop();
		long time = getRunningTime();
		for(Cutoff cutoff : Cutoff.values())
		{
			if(time < cutoff.getTime())
				return cutoff.format(time);
		}
		return Cutoff.ns.format(time);
	}
}
